Catalytic converter system with control and methods for use therewith

ABSTRACT

Aspects of the subject disclosure may include, for example, a catalytic converter system that includes a catalytic converter having a plurality of passages to facilitate at least one catalytic reaction in an exhaust gas from a vehicle engine. A temperature sensor generates a temperature signal indicating at least one temperature of the catalytic converter. An electromagnetic field generator that responds to a control signal by generating an electromagnetic field to inductively to heat the catalytic converter. A controller generates the control signal based on temperature signal. Other embodiments are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present U.S. Utility patent application claims priority pursuant to35 U.S.C. §119(e) to U.S. Provisional Application No. 62/041,053,entitled “THERMALLY MANAGED CATALYTIC CONVERTER CONTROL PROTOCOL”, filedAug. 23, 2014, which is hereby incorporated herein by reference in itsentirety and made part of the present U.S. Utility patent applicationfor all purposes.

The present U.S. Utility patent application also claims prioritypursuant to 35 U.S.C. §120 as a continuation-in-part of U.S. Utilityapplication Ser. No. 14/452,800, entitled “CATALYTIC CONVERTERSTRUCTURES WITH INDUCTION HEATING”, filed Aug. 6, 2014, which claimspriority pursuant to 35 U.S.C. §119(e) to U.S. Provisional ApplicationNo. 61/910,067, entitled “CATALYTIC CONVERTER USING FIELD HEATING OFMETAL COMPONENT”, filed Nov. 28, 2013, and U.S. Provisional ApplicationNo. 61/879,211, entitled “CATALYTIC CONVERTER EMPLOYINGELECTROHYDRODYNAMIC TECHNOLOGY”, filed Sep. 18, 2013, all of which arehereby incorporated herein by reference in their entirety and made partof the present U.S. Utility patent application for all purposes.

FIELD OF THE DISCLOSURE

This disclosure relates to a structures and methods of operation ofcatalytic converters for treating vehicle exhaust gases.

BACKGROUND

The U.S. Department of Transportation (DOT) and the U.S. EnvironmentalProtection Agency (EPA) have established U.S. federal rules that setnational greenhouse gas emission standards. Beginning with 2012 modelyear vehicles, automobile manufacturers required that fleet-widegreenhouse gas emissions be reduced by approximately five percent everyyear. Included in the requirements, for example, the new standardsdecreed that new passenger cars, light-duty trucks, and medium-dutypassenger vehicles had to have an estimated combined average emissionslevel no greater than 250 grams of carbon dioxide (CO₂) per mile invehicle model year 2016.

Catalytic converters are used in internal combustion engines to reducenoxious exhaust emissions arising when fuel is burned as part of thecombustion cycle. Significant among such emissions are carbon monoxideand nitric oxide. These gases are dangerous to health but can beconverted to less noxious gases by oxidation respectively to carbondioxide and nitrogen/oxygen. Other noxious gaseous emission products,including unburned hydrocarbons, can also be converted either byoxidation or reduction to less noxious forms. The conversion processescan be effected or accelerated if they are performed at high temperatureand in the presence of a suitable catalyst being matched to theparticular noxious emission gas that is to be processed and converted toa benign gaseous form. For example, typical catalysts for the conversionof carbon monoxide to carbon dioxide are finely divided platinum andpalladium, while a typical catalyst for the conversion of nitric oxideto nitrogen and oxygen is finely divided rhodium.

Catalytic converters have low efficiency when cold, i.e. the runningtemperature from ambient air start-up temperature to a temperature ofthe order of 300 C or “light-off” temperature, being the temperaturewhere the metal catalyst starts to accelerate the pollutant conversionprocesses previously described. Below light-off temperature, little tono catalytic action takes place. This is therefore the period during avehicle's daily use during which most of the vehicle's pollutingemissions are produced. Getting the catalytic converter hot as quicklyas possible is important to reducing cold start emissions.

BRIEF DESCRIPTION OF THE DRAWINGS

For simplicity and clarity of illustration, elements illustrated in theaccompanying figure are not drawn to common scale. For example, thedimensions of some of the elements are exaggerated relative to otherelements for clarity. Advantages, features and characteristics of thepresent disclosure, as well as methods, operation and functions ofrelated elements of structure, and the combinations of parts andeconomies of manufacture, will become apparent upon consideration of thefollowing description and claims with reference to the accompanyingdrawings, all of which form a part of the specification, wherein likereference numerals designate corresponding parts in the various figures,and wherein:

FIG. 1 is a perspective outline view of a catalytic converter brickbeing formed in an extrusion process.

FIG. 2 is a longitudinal sectional view of a known form of catalyticconverter.

FIG. 3 is a longitudinal sectional view of a catalytic converterassembly according to an embodiment of the disclosure.

FIG. 4 is a cross-sectional view of a catalytic converter according toanother embodiment of the disclosure.

FIG. 5 is a cross-sectional view of a fragment of a catalytic convertersubstrate according to an embodiment of the disclosure.

FIG. 6 is a longitudinal sectional view of the substrate fragmentillustrated in FIG. 5 taken on the line B-B of FIG. 5.

FIG. 7 is a perspective end view of a larger fragment corresponding tothe small substrate fragment shown in FIGS. 5 and 6.

FIG. 8 is a perspective end view similar to FIG. 7 but showing acatalytic converter substrate according to another embodiment of thedisclosure.

FIG. 9 is a side view of a wire insert for use in a catalytic convertersubstrate of the form shown in FIG. 8.

FIG. 10 is a longitudinal sectional view of a fragment of a catalyticconverter substrate showing the wire insert of FIG. 9 inserted into thesubstrate.

FIG. 11 is a longitudinal sectional view of a fragment of a catalyticconverter substrate showing an inserted wire insert according to anotherembodiment of the disclosure.

FIG. 12 is a cross-sectional view of a fragment of a catalytic convertersubstrate according to a further embodiment of the disclosure.

FIG. 13 is a longitudinal sectional view of the substrate fragmentillustrated in FIG. 12.

FIG. 14 is a perspective end view of a fragment of a catalytic convertersubstrate and emitter and collector electrodes illustrating anembodiment of the disclosure.

FIG. 15 is a perspective end view of a fragment of a catalytic convertersubstrate and emitter and collector electrodes illustrating analternative embodiment of the disclosure.

FIG. 16 is a perspective end view of a fragment of a catalytic convertersubstrate and collector electrode illustrating a further embodiment ofthe disclosure.

FIG. 17 is a perspective end view of fragments of a catalytic convertersubstrate and emitter electrode and, to a larger scale, a collectorelectrode, illustrating another embodiment of the disclosure.

FIG. 18 is a schematic view of a catalytic converter system according toan embodiment of the disclosure.

FIG. 19 is a block diagram representation of a feedback control loopaccording to an embodiment of the disclosure.

FIG. 20 presents graphical representations of a control signal andcatalytic converter temperature according to an embodiment of thedisclosure.

FIG. 21 is a block diagram representation of a controller according toan embodiment of the disclosure.

FIG. 22 is a flow diagram representation of a method according to anembodiment of the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE INCLUDING THE PRESENTLY PREFERREDEMBODIMENTS

A catalytic converter may take any of a number of forms. Typical ofthese is a converter having a cylindrical substrate of ceramic material,generally called a brick, an example of which is shown in FIG. 1. Thebrick 10 has a honeycomb structure in which a number of small areapassages or cells 12 extend the length of the brick, the passages beingseparated by walls 14. There are typically from 400 to 900 cells persquare inch of cross-sectional area of the substrate unit and the wallsare typically in the range 0.006 to 0.008 inches in thickness. Asindicated in FIG. 1, the ceramic substrates are formed in an extrusionprocess in which green ceramic material is extruded through anappropriately shaped die and units are cut successively from theextrusion, the units being then cut into bricks which are shorter than aunit. The areal shape of the passages or cells 12 may be whatever isconvenient for contributing to the overall strength of the brick whilepresenting a large contact area at which flowing exhaust gases caninteract with a hot catalyst coating the interior cell walls.

The interiors of the tubular passages in the bricks are wash-coated witha layer containing the particular catalyst material. A suitablewash-coat contains a base material, suitable for ensuring adherence tothe cured ceramic material of the substrate, and entrained catalystmaterial for promoting specific pollution-reducing chemical reactions.Examples of such catalyst materials are platinum and palladium which arecatalysts effective in converting carbon monoxide and oxygen to carbondioxide, and rhodium which is a catalyst suitable for converting nitricoxide to nitrogen and oxygen. Other catalysts are known which promotehigh temperature oxidation or reduction of other gaseous materials. Thewash-coating is prepared by generating a suspension of the finelydivided catalyst in a ceramic paste or slurry, the ceramic slurryserving to cause the wash-coat layer to adhere to the walls of theceramic substrate. As an alternative to wash-coating to place catalystmaterials on the substrate surfaces, the substrate material itself maycontain a catalyst assembly so that the extrusion presents catalystmaterial at the internal surfaces bounding the substrate passages orcells.

A catalytic converter may have a series of such bricks, each having adifferent catalyst layer depending on the particular noxious emission tobe neutralized. Catalytic converter bricks may be made of materialsother than fired ceramic, such as stainless steel. Also, they may havedifferent forms of honeycombed passages than those described above. Forexample, substrate cells can be round, square, hexagonal, triangular orother convenient section. In addition, if desired for optimizingstrength and low thermal capacity or for other purposes, some of theextruded honeycomb walls can be formed so as to be thicker than other ofthe walls, or formed so that there is some variety in the shape and sizeof honeycomb cells. Junctions between adjacent interior cell walls canbe sharp angled or can present curved profiles.

Typically, as shown in FIG. 2, the brick 10 is a wash-coated ceramichoneycomb brick wrapped in a ceramic fibrous expansion blanket 16. Astamped metal casing or can 18 transitions between the parts of theexhaust pipe fore and aft of the catalytic converter so as to encompassthe blanket wrapped brick. The casing 18 is typically made up of twoparts which are welded to seal the brick in place. The expansion blanketprovides a buffer between the casing and the brick to accommodate theirdissimilar thermal expansion coefficients. The sheet metal casingexpands many times more than the ceramic at a given temperature increaseand if the two materials were bonded together or in direct contact witheach other, destructive stresses would be experienced at the interfaceof the two materials. The blanket also dampens vibrations from theexhaust system that might otherwise damage the brittle ceramic.

In use, the encased bricks are mounted in the vehicle exhaust line toreceive exhaust gases from the engine and to pass them to the vehicletail pipe. The passage of exhaust gases through the catalytic converterheats the brick to promote catalyst activated processes where theflowing gases contact the catalyst layer. Especially when the vehicleengine is being run at optimal operating temperature and when there issubstantial throughput of exhaust gases, such converters operatesubstantially to reduce the presence of noxious gaseous emissionsentering the atmosphere. Such converters have shortcomings however atstart-up when the interior of the brick is not at high temperature andduring idling which may occur frequently during city driving or whenwaiting for a coffee at a Tim Hortons drive-through.

Converter shape, profile and cell densities vary among differentmanufacturers. For example, some converter bricks are round and some areoval. Some converter assemblies have single stage bricks that aregenerally heavily wash-coated with the catalyst metals, while others mayhave two or three converter bricks with different wash-coatings on eachbrick. Some exhausts have 900, 600 and 400 cell per square inch (cpsi)cell densities used in the full exhaust assembly, while others use only400 cpsi bricks throughout. A close-coupled converter may be mounted upclose to the exhaust manifold with a view to reducing the period betweenstart-up and light-off. An underfloor converter can be located furtherfrom the engine where it will take relatively longer to heat up but berelatively larger and used to treat the majority of gases once theexhaust assembly is up to temperature. In another configuration, a unitfor reducing the period to light-off and a unit to deal with high gasflow after light-off are mounted together in a common casing.

At one or more locations in the converter assembly, sensors are mountedin the exhaust gas flow provides feedback to the engine control systemfor emission checking and tuning purposes. Aside from start-up, controlof fuel and air input has the object typically of maintaining a 14.6:1air:fuel ratio for an optimal combination of power and cleanliness. Aratio higher than this produces a lean condition—not enough fuel. Alower ratio produces a rich condition—too much fuel. The start-upprocedure on some vehicles runs rich for an initial few seconds to getheat into the engine and ultimately the catalytic converter. Thestructures and operating methods described below for indirectly heatingthe catalyst layers and the exhaust gases can be used with each of aclose-coupled catalytic converter, an underfloor converter, and acombination of the two.

FIG. 3 shows an assembly having two bricks of the sort illustrated inFIGS. 1 and 2, but in which one brick is modified to enable inductionheating. Induction heating is a process in which a metal body is heatedby applying a varying electromagnetic field so as to change the magneticfield to which the metal body is subject. This, in turn, induces eddycurrents within the body, thereby causing resistive heating of the body.In the case of a ferrous metal body, heat is also generated by ahysteresis effect. When the non-magnetized ferrous metal is placed intoa magnetic field, the metal becomes magnetized with the creation ofmagnetic domains having opposite poles. The varying field periodicallyinitiates pole reversal in the magnetic domains, the reversals inresponse to high frequency induction field variation on the order of1,000 s to 1,000,000 s cycles per second (Hz) depending on the material,mass, and shape of the ferrous metal body. Magnetic domain polarity isnot easily reversed and the resistance to reversal causes further heatgeneration in the metal.

As illustrated in FIG. 3, surrounding the ceramic substrate is a metalcoil 20 and, although not shown in the figure, located at selectedpositions within the ceramic substrate 10 are metal elements which maytake any of a number of forms. By generating a varying electromagneticfield at the coil 20, a chain reaction is initiated, the end result ofwhich is that after start-up of a vehicle equipped with an exhaustsystem embodying the disclosure, light-off may be attained more quicklyin the presence of the varying electromagnetic induction field than ifthere were no such field. The chain reaction is as follows: the varyingelectromagnetic field induces eddy currents in the metal elements; theeddy currents cause heating of the metal elements; heat from the metalelements is transferred to the ceramic substrate 10; heat from theheated substrate is transferred to exhaust gas as it passes through theconverter; and the heated exhaust gas causes the catalytic reactions totake place more quickly compared to unheated exhaust gas.

The coil 20 is a wound length of copper tube, although other materialssuch as copper or litz wire may be used. Copper tube is preferredbecause it offers high surface area in terms of other dimensions of thecoil; induction being a skin-effect phenomenon, high surface area is ofadvantage in generating the varying field. If litz wire or copper wireis used, an enamel or other coating on the wire is configured not toburn off during sustained high temperature operation of the converter.

A layer of 22 of electromagnetic field shielding material such asferrite is located immediately outside the coil 20 to provide aninduction shielding layer and reduces induction loss to the casing 18.The ferrite shield 22 also acts to increase inductive coupling to theceramic substrate 10 to focus heating.

The coil is encased in cast and cured insulation. The cast insulationfunctions both to stabilize the coil position and to create an air-tightseal to confine passage of the exhaust gases through the brick 10 wherethe catalytic action takes place. The insulation also provides a barrierto prevent the coil 20 from shorting on the casing 18 or the ferriteshield 22. The insulation is suitable alumino-silicate mastic. In analternative embodiment, the converter is wrapped in an alumino-silicatefibre paper. In one manufacturing method, a copper coil 20 is wrappedaround the ceramic substrate 10 and then placed in the casing 18. In analternative manufacturing method, the coil 20 is placed in the casing 18and the ceramic substrate 10 is inserted into the coil can assembly.

In one embodiment of the disclosure, a varying electromagnetic inductionfield is generated at the coil by applying power from either a DC or ACsource. Conventional automobiles have 12 VDC electrical systems. Theinduction system can operate on either DC or AC power supply. Theinduction signal produced can also be either DC or AC driven. For eitherDC or AC, this produces a frequency of 1 to 200 kHz, a RMS voltage 130Vto 200V and amperage of 5 to 8 A using 1 kw of power as an example. Inone example suitable for road vehicles, a DC to DC bus converts thevehicle's 12 VDC battery power to the required DC voltage outlinedabove. In another example suitable for conventional road vehicles, a DCto AC inverter converts the vehicle's 12V DC battery power to thedesired AC voltage outlined above. Another example is more suited tohybrid vehicles having both internal combustion engines and electricmotors have on-board batteries rated in the order of 360V voltage and 50kW power. In this case, the battery supply power is higher, but the samebasic DC to DC bus or DC to AC inverter electrical configuration can beapplied. An IGBT high speed switch is used to change the direction ofelectrical flow through the coil. In terms of the effect of a varyingelectromagnetic induction field on metal in the ceramic substrate, a lowswitching frequency produces a longer waveform providing good fieldpenetration below the surface of the metal element and thereforerelatively uniform heating. However, this is at the sacrifice of hightemperature and rapid heating owing to the lack of switching. Incontrast, a high switching frequency produces a shorter waveform, whichgenerates higher surface temperature at the sacrifice of penetrationdepth. Applied power is limited to avoid the risk of melting the metalelements. A suitable power input to a single brick coil is of the orderof 1.1 kw.

As previously described, metal elements are located at selectedlocations of the ceramic substrate 10. For two identical metal elements,generally, a metal element closer to the source of the induction fieldbecomes hotter than an equivalent metal element located further awayfrom the source because there is an increase in efficiency; i.e. thelevel of induction achieved for a given power input. With a regularinduction coil 10 as illustrated, metal elements at the outside of thebrick 10 are near to the coil 20 and become very hot, while anequivalent metal element near the substrate center remains relativelycool. An air gap 26 between the coil 20 and the nearest inductance metalelements prevents significant heat transfer from the inductance metalelements to the coil which would otherwise increase the coil resistivityand so lower its efficiency. In an alternative embodiment, a relativelyhigher concentration of the metal elements is sited towards the centerof the ceramic substrate to compensate for the fact that the fieldeffect from the coil source is considerably less near the centre of thesubstrate than near the outer part of the substrate. In a furtherembodiment, a relatively higher metal element load is located at someintermediate position between the centre and perimeter of the ceramicsubstrate, whereby heat generated within the intermediate layer flowsboth inwardly to the center and outwardly to the perimeter for moreefficient overall heating. The coil 20 is sized to the metal load toachieve high efficiency in terms of generating heat and in terms ofspeed to light-off.

The electromagnetic induction field can be tuned to modify heatingeffects by appropriate selection of any or all of (a) the electricalinput waveform to the coil, (b) nature and position of passive fluxcontrol elements, and (c) nature, position, and configuration of thecoil 20. For example, the induction field is tuned to the location ofmetal elements or to the location of high concentration of such elementsin the ceramic substrate 10. Alternatively, or in addition, the appliedfield is changed with time so that there is interdependence between theinduction field pattern and the particular operational phase frompre-start-up to highway driving. In an alternative configuration, morethan one coil can be used to obtain desired induction effects. Forexample, as shown in the cross sectional view of FIG. 4, the ceramicsubstrate 10 has an annular cross-section with a first energizing coil20 at the substrate perimeter and a second energizing coil at thesubstrate core.

As shown in the fragmentary sectional views of FIGS. 5 and 6, in oneembodiment of the disclosure, the metal elements are metal particles 28which are embedded in the walls 14 of the ceramic honeycomb substrate,the particle size being less than the width of walls 14. As part of themanufacturing process, the metal particles are added and mixed with aceramic base material while the ceramic is still green or flowable; i.e.before it is extruded. In this way, the particles are distributedrelatively evenly throughout the ceramic base material to be extruded.In operation of this embodiment, when a varying electromagneticinduction field is applied from the coil 20, the ceramic material in thesubstrate is comparatively invisible to the applied field and thereforedoes not heat up. The metal particles 28 heat up and conduct heat to thewalls 14 of the ceramic honeycomb within which they are bound.

In an alternative manufacturing embodiment, mixing of the ceramic basematerial with metal particles and subsequent extrusion of the mixture toform the honeycomb substrate are configured so that selected locationsin the substrate have a greater metal particle concentration than otherlocations. Such a configuration may be attained by bringing together atthe extruder several streams of green ceramic material, with the streamshaving different levels of metal content from one another. The streamsare then fused immediately before extrusion so that the variation inmetal content is mirrored across the cross-section of the extrudedsubstrate. In a further embodiment, metal particles are used that areelongate or otherwise asymmetric so that they tend to align somewhatcloser to converter cell walls in the course of the extrusion process.In another embodiment, the particle lengths are made sufficiently longthat at least some adjacent particles come into electrical contact witheach other in the course of mixing or subsequent extrusion.

In alternative embodiments of the disclosure, the metal elements arelocated within the ceramic honeycomb structure, but not embedded withinthe material of the honeycomb structure itself. For example, duringpost-processing of ceramic substrate bricks, metal elements arepositioned in selected cells 12 of the substrate or brick 10. In oneimplementation as illustrated in FIG. 7, a high concentration of metalparticles is mixed with a mastic and the resulting mixture is injectedusing a method such as that described in copending utility patentapplication Ser. No. 13/971,129 (A catalytic converter assembly andprocess for its manufacture), filed Aug. 20, 2013, the disclosure ofwhich application is incorporated herein by reference in its entiretyand made part of the present application for all purposes. Followinginjection, injected threads 30 of the mastic mixture is cured by, forexample, microwave heating as described in copending utility patentapplication Ser. No. 13/971,247 (A catalytic converter assembly andprocess for its manufacture) filed Aug. 20, 2013, the disclosure ofwhich application is also incorporated herein by reference in itsentirety and made part of the present application for all purposes. Inone implementation, the mastic base material is a low viscosity,paste-like mixture of glass fibers, clay slurry, polymer binder andwater, from which the water and the organic binder are driven off in thecourse of the curing process. Following curing, the injected threads 30are predominantly silica in a porous matrix of silica, ceramic and metalparticles.

In another exemplary configuration (not shown), selection of passages incell 12 to be injected is made so that the threads of cured mastic metalmixture are not uniformly distributed, but generally occupy anintermediate annular zone of the cylindrical substrate. In the operationof such a structure, heat is preferentially generated at the annularzone and is transferred from the zone sites inwardly towards thesubstrate core and outwardly towards its perimeter. It is preferred thatmetal particles within the mastic metal mixture injected into a cell arepredominantly situated close to the cell interior surface rather thantowards the cell center so as to localize heat generation near the cellsurfaces and to get greater heat transfer and speed of such transfer tothe ceramic substrate. Appropriately directed agitation of the loadedconverter brick after during and/or after extrusion and before curingcan encourage some migration of metal particles towards the cell walls.

In injected cell implementations, any cell which is blocked with athread of the mastic and metal particles cannot function to catalyze apollution-reducing reaction as exhaust gas passes through the cell. Sucha plugged cell is used solely for heating at start-up or when idling.Consequently, only selected ones of the cells are filled with thecomposite heating material. In the example illustrated, the substratehas 400 cells per square inch. Of these, from 8 to 40 cells per squareinch are filled with the metal mastic composite depending on the radialposition of the cells and such that over the full areal extent of thesubstrate, the blocked cells occupy from 2 to 10% of the substrate area.

In a further embodiment of the disclosure, discrete metal elements thatare larger than the particle sizes discussed with the FIG. 7 embodimentare inserted at selected cell locations in the catalytic convertersubstrate. As shown in FIG. 8, exemplary metal elements are wires 32which are positioned within selected substrate cells and which extendalong the full length of the cells from the brick entrance to its exit.The inserted wires 32 may, for example, be of round, square or othersuitable cross-section. As shown in the FIG. 8 embodiment, the ceramicconverter substrate 10 has square cells and round section wires. Squaresection wires provide better heat transfer to the square section cellsdue to high contact area between the two materials. However, roundsection wires are easier to insert into the square section cells owingto there being less surface area contact causing insertion resistance.The wires may be fixed into their respective cells by a friction fitwhich is at least partially achieved by closely matching the wireexterior area dimensions to the cell area dimensions so that surfaceroughness of the wire surface and the cell walls locks the wires inplace. Wire is drawn to be from 0.002 inches to 0.005 inches less inwidth than the cell width to enable insertion.

In one configuration, an insert 34 is formed of wire to have a bow-shapeas shown in FIGS. 9 and 10. The bowed wire 34 has memory so that afterthe bow is straightened as the wire is inserted into a cell 12, theinsert 34 tends to return to its bow shape causing center and endregions of the wire to bear against opposed sides or corners of the cell12 and so enhance the friction fit to retain the wire in place in thecell. Alternatively, or in addition, wires 36 are crimped at their endsas shown in the embodiment of FIG. 11 so as to establish end bearingcontact sites. The overall friction fit in each case is such as toresist gravity, vibration, temperature cycling, and pressure on thewires as exhaust gases pass through the converter.

Wires may alternatively, or in addition, be fixed into the cells bybonding outer surfaces of the wires to interior surfaces of respectivecells. In exemplary bonding processes, the wire is at least partiallycoated with an adhesive/mastic before insertion, or a small amount ofadhesive/mastic is coated onto the cell interior walls before wireinsertion. High temperature mastic materials and composite adhesives areused. Suitable mastic, for example, is of the same form as that used inthe injection embodiments previously described. A composite adhesive,for example, is a blend of ceramic and metal powders with a bindertransitioning between the two main materials. Such a blend is used tominimize temperature cycling stress effects in which there may besignificant metal wire expansion/contraction, but vanishingly smallexpansion/contraction of the ceramic substrate. This differential canproduce stresses at the adhesive interface between the two materials. Byusing such a composite adhesive, movement of a bonded wire relative tothe surrounding cell surface is minimized and heat transfer increasedheat transfer is obtained by the presence of the composite adhesivematerial.

As shown in the embodiment of FIG. 8, an array of wires having a uniformdistribution through the array of converter cells is used. In oneexample, 1 wire is inserted for every 25 cells of a 400 cpsi substrate.This has a satisfactory heating performance and not too great anocclusion of converter cells from the viewpoint of pollution-cleaningcatalytic reactions implemented at the converter. A significantly higherratio of wires to cells can result in slower heating to light-offbecause of the high overall thermal capacity represented, in total, bythe wires and because of the fact that some wires block the “line ofsight” field effect on other wires. In contrast, while a significantlylower ratio of wires to cells results in fewer occlusions of convertercells, a sparse distribution of metal of the order of less than 1 wireinserted for every 49 cells in a 400 cpsi substrate results in reducedheat generation and increased time to light-off. As in the case of theinjected metal particle embodiments described previously, wires can beinserted in a non-uniform pattern: for example, to a generally annularconcentration of wire insertions at an intermediate radial positionwithin the ceramic converter substrate; or to position a greaterconcentration of wires near the core of the converter furthest from thecoil compared to the concentration of wires near the perimeter of theconverter.

There are advantages and disadvantages as between using metal particlesand larger metal elements such as wire inserts. Induction heatingproduces a “skin-effect” hot surface of the metal being heated. Thismakes the surface area of the metal element important to efficientheating. Generally, the more surface area there is, the quicker themetal heats-up. However, induction is a line-of-sight process where thesurface that “sees” the inductive field is the one that heats-up firstand gets hotter. Powder particles heat-up quickly and larger bodiesheat-up more slowly. In the case of particles, whether dispersed andembedded in the ceramic substrate material itself or in mastic injectedinto selected cells, each particle acts independently of the next sothere is little conduction between neighboring particles. Consequently,heat distribution may be relatively poor. Larger metal bodies conductheat well throughout their bulk and so are preferred in terms ofdistributing heat. The thin wire embodiments of FIG. 8 offer a goodcompromise between particles and solid bodies in terms of surface area,line-of-sight positioning and conduction characteristics all of whichsignificantly affect the heating performance.

Conduction is the primary source of heat transfer to the ceramicsubstrate and therefore to the exhaust gases when the converter is inoperation. In the case of the wire insert embodiments, there is also asmall amount of convective heat transfer but this is limited as there isonly a small air gap between the wires and the interior surface of thecells so air movement is minimized. There is also a relatively smallamount of radiation heat transfer in the case such as inserted wireswhere the wires are separated over a large part of their surface areafrom the interior of the cells but where the separation is not occluded.

As previously described and illustrated, a preferred distribution ofinductance metal elements relative to the position of cells isconfigured so that the heating effect is generally uniform across thearea of the converter. Especially for start-up and idling, wherenon-uniform exhaust gas flow patterns may develop, there may beadvantage in deliberately developing a heat pattern across the converterwhich is not uniform. As previously noted, this may be achieved byappropriately siting inductance metal elements in selected cells. It mayalso be achieved in another embodiment of the disclosure by usingdifferently sized or shaped metal inserts or by using differentconcentrations of particles in the injection embodiments. It may beachieved in a further alternative structure and method by generating anon-radially symmetrical field or generating two or more interferingfields. Such induction fields and their interaction could, for example,be varied in the period from start-up to light-off. Changing heatingeffects may also be achieved using a combination of such inductancemetal siting and field manipulation. Targeted heating that varies inposition, time, or both can be implemented with a view to increasingconversion of pollutants, to saving power, or for other reasons.

In another embodiment of the disclosure, the metal elements are notentrained within the material of the ceramic substrate and are notinjected or positioned into selected cells. Instead, as shown in thefragmentary section views of FIGS. 12 and 13, a ferrous metal coating 38is formed on the interior surfaces of walls 14 of selected convertercells before application of the catalyst(s) coating 40. Alternatively,(not shown) the ferrous metal coating is laid down as a common coatingwith the catalyst metal(s), either by using alloy particles that containboth the ferrous metal and the catalyst metal(s) or by having a wash inwhich both the ferrous metal particles and the catalyst metal particlesare dispersed. In the latter arrangements, there may be some loss ofcatalyst action arising from the ferrous metal taking some of thecatalyst metal sites and so a compromise is necessary.

All metals are responsive to some extent to an induction field, withferrous metals being the materials most readily heated by such a field.Catalyst materials contained within a wash coat applied to a honeycombsubstrate cell interior are typically platinum group metals—platinum,palladium and rhodium. Such materials have a low magnetic permeabilityof the order of 1×10⁻⁶ (in the case of platinum) and so are influencedonly very slightly by an applied induction field. Moreover, catalystmetals are present in very tiny amounts of the order of a gram perconverter brick so there is insufficient metal in the catalyst assemblyto generate and transfer any noticeable heat to the ceramic substrate instart-up period or idling periods. In contrast, ferrous metals used forthe induction heating are present in an amount of the order of 60 to 200grams per brick and have magnetic permeability of the order of 2.5×10⁻¹in the case of iron.

As previously indicated, induction heating is applied in the periodbefore light-off in order to reduce the amount of harmful pollutantswhich are emitted before the catalyst coatings have reached atemperature at which they start to catalyze reactions in which thepollutants are converted to more benign emissions. Particularly for citydriving, engine operation is frequently characterized by bursts ofacceleration and braking punctuated by periods of idling. At such times,the temperature of the exhaust gas entering the converter and the wallsof the substrate with which the flowing exhaust gas is in contact maystart to fall. If the idling and the cooling continue, the temperatureof the substrate and the gas fall below that required for thepollutant-reducing catalytic reactions to occur. In such periods,heating of the converter substrate is obtained by switching on theinduction heating. At a future point, when the vehicle is no longeridling and the exhaust gas temperature increases past the temperaturerequired for effective catalytic reaction to convert the toxic exhaustgas pollutants to relatively benign products, the induction heating isswitched off.

Embodiments of the induction heating disclosure have been described inthe context of ferrous alloys such as steel which are commerciallyavailable in common shapes and sizes, and at reasonable cost.Alternative ferromagnetic metals such as cobalt or nickel or theiralloys may also be used. The metal used must survive high temperaturereached by the catalytic converter and repeated temperature cycling asthe metal intrusions move repeatedly from a cold start to operatingtemperature and back again. Generally, alloying of iron or otherferromagnetic metal gives advantageous mechanical and physicalproperties such as corrosion/oxidation resistance, high temperaturestability, elastic deformation, and formability.

Referring to FIGS. 14 to 17, embodiments of the disclosure areillustrated which are adapted for electrohydrodynamic (EHD) heat andmass transfer of exhaust gas passing through the passages or cells of acatalytic converter substrate. In the EHD process, free electrons aregenerated and caused to migrate from a charged upstream emitter to agrounded downstream collector 44. In the course of their migration,electrons collide with molecules in the exhaust gas, transferringmomentum to the gas molecules and causing turbulence in the gas flow.This means that there is a lesser tendency for the gas flow through thecells to adopt a laminar flow and/or there is a tendency for a laminargas flow to depart from laminarity. Both tendencies bring more exhaustgas into contact with the walls of the converter substrate cell wallsthan would be the case without EHD stimulation. This results in both anincrease in heat transfer between the exhaust gas and the walls of thesubstrate and an increase in the catalytic pollution-reducing reactionsowing to increased contact of the exhaust gas with hot catalyst at theinterior surfaces of the substrate cell walls.

In operation, in the period between start-up and light-off, thesubstrate walls are at a lower temperature than the exhaust gas. Moreheat is transferred from the flowing exhaust gas to the substrate bystimulation of EHD heat transfer stimulation and the substratetemperature increases at a faster rate than would be the case withoutthe EHD heating process. A control circuit includes a first temperaturesensor to monitor the temperature of the converter substrate and asecond temperature sensor to monitor the temperature of the exhaust gasimmediately upstream of the converter. The control circuit includes acomparator for measuring the difference between the exhaust gas and theconverter substrate temperatures and a switch controlled by thecomparator to switch on EHD voltage to the emitter. Greater speed tolight-off is obtained by switching in the EHD heat transfer process tostimulate heat transfer from the exhaust gas during the start-up tolight-off period. At a future point, when the substrate is sufficientlyhot to cause the pollution reducing catalytic reaction to occur, EHDheat transfer stimulation is switched off.

In addition, during idling periods, the temperature of the exhaust gasentering the converter may start to drop and a situation may arise wherethe catalytic converter substrate walls are still at an optimaltemperature for catalyst reactions, but the gas entering the converteris below a temperature that it is optimal for such reactions. During theidling phases, the converter may remain at or near an optimal operatingtemperature from the viewpoint of reducing harmful emissions, even asthe gas flowing through the converter is cooling down. In such periods,low power heating of the cooling exhaust gas is obtained by switching inthe EHD heat transfer process to draw heat for a limited period of time.At a future point, when the vehicle is no longer idling and the exhaustgas temperature increases past the monitored substrate temperature, theEHD heat transfer stimulation can be switched off.

Referring in detail to FIG. 14, for operating a catalytic converter inwhich EHD is implemented, an emitter 42 is connected to a 25 to 50kilovolts power source delivering very low amperage, the systemtherefore consuming only a few watts and a collector 44 is grounded. Theflow of electrons produces preferential heat exchange between thecharged exhaust gas and the converter substrate compared with thepassage through the catalytic converter of uncharged exhaust gas. Theconductivity of the exhaust gas influences the extent of mixing and flowchanges that, in turn, cause more rapid heat transfer between theconverter substrate and the exhaust gas. Generally, the more conductivethe exhaust gas, the higher the turbulent effect and the greater the EHDheat transfer effect.

As shown in the FIG. 14 embodiment, in a first emitter collectorarrangement, the emitter 42 is a regular mesh of 0.25 inch diameter rodsand 0.375 inch apertures, the mesh mounted immediately upstream of thebrick 10. A collector 44 is a similar metal mesh located immediatelydownstream of the converter brick, this mesh being connected to ground.Interconnection of the upstream mesh to a positive voltage source andinterconnection of the downstream mesh to ground provides the positive(emitter) and negative (collector) electrodes required to generateelectron flow.

As shown in FIG. 15, in a second emitter collector arrangement, aconfiguration of wire inserts is used similar to that shown in FIG. 8except that the wire inserts are interconnected to each other and toground. In the illustrated configuration, a continuous wire 46 is usedand is looped in and out of substrate cells so that adjacent wireinserts are effectively stitched into place.

In another embodiment, as shown in FIG. 16, the mesh collector 44 hasprotruding wires 48 that are aligned with the longitudinal axis ofselected substrate cells. In the course of manufacture, the protrudingwires 48 of the collector 44 are slid back towards the front end of theconverter brick and into the aligned cells 12. The mesh collector islocked to the back side of the substrate. In one form, the protrudingwires 48 have a friction fit within the selected cells 12 as previouslydescribed with reference to FIGS. 8 to 11 or are secured in place usinga suitable adhesive. In another form and associated method, theprotruding wires are pre-located in the selected cells and then bound inplace by injecting a metal mastic matrix into the cell and then dryingand sintering the matrix.

In a further emitter collector arrangement as shown in FIG. 17, theemitter 42 is a metal sphere having a diameter matching the diameter ofa cylindrical converter substrate, the sphere being devoid of angularcorners so that electron emission is relatively evenly distributedacross its surface. A series of collectors are formed by fillingselected converter cells 12 with a metal powder in a binder matrix toconstitute a series of collector sites, the collector threads 30 withinthe plugged cells being connected together and to ground by, forexample, a mesh of the form shown in FIG. 16 but with relatively shortercontact projections 48. The metal particles are mixed with a mastic andthe resulting mixture is injected using a method such as that describedin copending utility patent application Ser. No. 13/971,129 (A catalyticconverter assembly and process for its manufacture), filed Aug. 20,2013, the disclosure of which application is incorporated herein byreference in its entirety and made part of the present application forall purposes. Following injection, injected threads 30 of the masticmixture are cured by, for example, microwave heating as described incopending utility patent application Ser. No. 13/971,247 (A catalyticconverter assembly and process for its manufacture) filed Aug. 20, 2013,the disclosure of which application is also incorporated herein byreference in its entirety and made part of the present application forall purposes. In one implementation, the mastic base material is a lowviscosity, paste-like mixture of glass fibers, clay slurry, polymerbinder and water, from which the water and the organic binder are drivenoff in the course of the curing process. Following curing, the injectedthreads 30 are predominantly silica in a porous matrix of silica,ceramic and metal particles.

In a modification (not shown) of the FIG. 17 embodiment, a uniformlydistributed first selection of cells is blocked with the metal bindermatrix, the cells being wired together and to each other to formemitters. An equal number of cells generally alternating in distributionwith the emitter cells are also blocked with metal binder matrix, thesecond set of cells being wired together and to ground to formcollectors. This arrangement has high efficiency at the surface ofsubstrate cells because the emitter and collector are integral parts ofthe substrate.

In further alternatives, the emitter and collector configurations shownpreviously can be matched differently.

A benefit of induction heating is that converter assemblies can besmaller. A cold start produces 75 to 90% of the pollutants of aninternal combustion engine and this drives the size of the overallexhaust assemblies. Since the induction heating technology addressesmuch of this 75 to 90%, there is the ability to shrink the converterpackage. By introducing added heat and mass transfer with theimplementation of an EHD sub-system, further size reduction is possible.

National emissions standard requirements are a prime driver forcatalytic converter design. The requirements are very high and difficultto meet by with a single converter. Currently, therefore, most cars nowin production employ a two converter assembly—one at a close-coupledposition and the other at an underfloor position. The close-coupledconverter is normally lighter in weight than the underfloor converterwhich means that is has low thermal capacity and so will attain acatalytic reaction operating temperature as quickly as possible.However, the close-coupled converter is of relatively lower efficiencycompared with the heavier underfloor converter once the two convertershave reached their respective catalytic reaction operating temperatures.By introducing induction heating to the exhaust process at start-up, itmay be manufacturers can return to a single converter installation andmeet emission standards by eliminating the need for the close-coupledconverter.

Although embodiments of the disclosure have been described in thecontext of ceramic catalytic converter substrates, stainless substratesubstrates can also be used, with induction heating being implemented ina similar way to that described above. Substrates made of 400 seriesmagnetic alloys are preferred because such alloys exhibit significantmagnetic hysteresis. With a surrounding coil, the outer annular regionsof small diameter stainless steel substrates heat up extremely quicklyowing to their small thermal capacity.

In the case of EHD heat and mass transfer, in an alternative embodimentof the disclosure using a stainless steel substrate, the catalyticconverter has two steel bricks with the first functioning as an emitterand the second as a collector. In such cases, insertion of wire insertsor injection and curing of metal mastic threads are obviated because thesteel bricks themselves function to emit and collect the free electrons.

Embodiments of the EHD heat and mass transfer disclosure have beendescribed in the context of ferrous alloys such as steel which arecommercially available in common shapes and sizes, and at reasonablecost. Alternative metals may be used for the EHD electrodes providedthat they can survive high temperature reached in the catalyticconverter and repeated temperature cycling as the metal elements in theconverter substrate body move repeatedly from a cold start to operatingtemperature and back again. Generally, alloying gives advantageousmechanical and physical properties such as corrosion/oxidationresistance, high temperature stability, elastic deformation, andformability.

In applying the induction heating and EHD mass and heat transferdisclosures to the structure and operation of a catalytic converter, theelectrical circuit and electrical inputs required to implement inductionheating are different from the are electrical circuit and electricalinputs required to implement EHD heat and mass transfer. In thisrespect, it is likely that the EHD effect is influenced by the appliedinduction field. This could be a positive influence with the inductionfield adding a zigzag component to the electron flow resulting inenhanced heat and mass transfer. Alternatively, the induction field mayeclipse the EHD effect.

The induction heating process and the EHD mass and heat transfer processmay be applied simultaneously or at separate times during, or in thecase of induction heating, immediately before start-up.

FIG. 18 is a schematic view of a catalytic converter system according toan embodiment of the disclosure. A catalytic converter system 75includes a catalytic converter 60 having a plurality of passages tofacilitate at least one catalytic reaction in an exhaust gas 56 from avehicle engine, generating processed exhaust gas 56′. One or moretemperature sensors 50 are coupled to the catalytic converter 60 togenerate temperature signals indicating at least one temperature of thecatalytic converter. The temperature sensors 50 can be implemented viathermocouples, thermistors or other thermal sensors that mounted on orin the catalytic converter in order to monitor the temperature atdifferent locations on or in the converter or via other temperaturemonitors.

Outputs from the temperature sensors 50 are taken to a controller 52 atwhich the monitored temperature or temperatures are used to control theinduction heating via control of an AC generator such as AC source 64.The controller 52 generates a control signal 58 based on thetemperature(s) indicated by these temperature signals. At least oneelectromagnetic field generator including AC source 64 and coil 20responds to the control signal 58 by generating an electromagnetic fieldto inductively to heat the catalytic converter 60. The AC source 64 can,for example, be a variable AC generator that generates an AC signalhaving a magnitude that varies as a function of the control signal 58.In another example, the control signal 58 turns the AC source 64 on andoff with a duty cycle that varies as a function of the magnitude of thedesired level of heating. The AC source can generate a signal such as a50 Hz or 60 Hz signal however medium frequency signals in the range 1kHz-100 kHz and radio frequency signals in the range of 100 kHz-10 MHzor other frequencies can likewise be employed.

Controller 52 can be implemented via a processor such as a standaloneprocessor or a shared processing device such as an engine controlmodule. The controller 52 uses one or more algorithms to control theapplied induction and EHD processes in implementations where theinduction field characteristics or the EHD high voltage characteristicsare selectable to achieve a particular induction heating pattern or EHDeffect. The controller 52 can be mounted independently of the catalyticconverter. For example, the controller 52 can be mounted inside thevehicle where the electronic control circuitry is relatively wellprotected. Alternatively, with a weatherproof casing, the convertercontrol module can be placed in the engine bay close to the battery orunder the vehicle close to the catalytic converter.

Consider an example where the catalytic converter 60 is implemented viaa bolt-in assembly in a vehicle to treat internal combustion engineemissions. Platinum group metals or other catalysts in the wash-coatingwork in combination with heat to treat the majority of pollutants in theexhaust gas. The catalytic treatment can be heavily dependent ontemperature. For the process to be effective, a minimum light-offtemperature of about 300 C may need to be reached and maintained. Theexhaust gas treatment process may rapidly drop in efficiency below thistemperature. In normal engine operation, there are several instanceswhere the temperature of the catalytic converter can be below thisthreshold: cold start, cool down and start-stop hybrid vehicleoperation.

In a cold start condition, the engine and exhaust system are at ambienttemperature. In really cold environments, this temperature can be as lowas −30 C on a regular basis in winter. Consequently, it can take severalminutes of engine operation before the engine and catalytic convertersheat up to the required temperature. In fact, there is little to noemissions treatment until the system gets up to the thresholdtemperature, typically referred to as “light-off”. Conventionalcatalytic converters are solely reliant on the engine for heat to raisetheir temperature.

Cool down occurs when the engine and exhaust system start out hot andthen the temperature drops below the threshold point. Excessive idlingafter the engine is hot can produce this effect. A low engine RPM willnot produce enough heat to keep the catalytic converter 60 hot. Thegradual cooling may result in a steady-state temperature that is belowthe light-off temperature. Decelerating from high speed can also producethis effect. The engine RPM drops to close to idling levels because nopower is required and, as in the case of idling, there is not enoughheat generated by vehicle exhaust to keep the catalytic converter 60hot. Also, there is a large amount of convection under the vehicle thatrobs heat from the engine and catalytic converter, thus adding to thecooling rate. The issues with current converter technology is the reasonthat idling bans have been put in place by the law makers and also whystop-and-go traffic can be so polluting.

In start-stop hybrid vehicle operation, the vehicle engine can beautomatically turned-off and restarted during vehicle operation. In mildhybrid vehicles, the vehicle engine is stopped by the engine controlmodule to avoid idling when a vehicle is at rest, such as when a vehicleis stopped in traffic. When the driver removes his/her foot from thebrake and engages the accelerator to resume motion, the engine controlmodule quickly restarts the engine is as little as 350 milliseconds. Inhybrid electric vehicles, the internal combustion engine can beturned-off for more extended periods and used only when necessary tosupplement the operation of one or more electric motors that operate viabattery power. Similar to the cold-start and cool-down conditionspreviously described, the catalytic converter may be at ambienttemperature or otherwise lower than light-off temperature.

The induction heating and EHD heat/mass transfer processes previouslydescribed enhance the performance of the emissions treatment by thecatalytic converter system 75 under normal driving conditions includingcold starts and cool down, etc. and otherwise improve emissionstreatment of exhaust gas 56 by the catalytic converter 60. Controloperations can include, but are not limited to:

-   -   (a) Pre-heat—heat catalytic converter before engine starts;    -   (b) Post-heat—heat catalytic converter following engine start;    -   (c) Hybrid—a combination of pre-heat and post-heat where the        catalytic converter is heated before and after engine start;    -   (d) Thermal Management—typically not associated with cold starts        but maintains the converter temperature above light-off with        rapid cooling; and/or    -   (e) Particulate filter regeneration        For example, once light-off temperature is achieved during        pre-heating, the controller 52 can enter a temperature        maintenance mode where the temperature is simply maintained and        not increased. The power demand in the maintenance mode is a        fraction of that required for continuous, intense heat-up.        Maintaining the temperature is accomplished either by pulsing        the full induction power on and off, or by modulating the power.        Pulsing is the more simple process in that the system is either        on or off with only a timer control being required. The        frequency and duration of pulses and the delay between pulses        are selected so that the temperature is maintained constant        within a few degrees. Modulating the power is more complex as        the power output is automatically adjusted with the objective of        maintaining a constant temperature. The more complex induction        circuit needs to be operable through a full range of outputs        from 0% or near zero (say min 20%) on through 100%. In one        embodiment, a maintenance mode is triggered upon cooling of the        catalytic converter while the engine is still running; for        example, in response to cooling when the vehicle engine is        idling. A pulsed or modulated operation similar to those        outlined above is used to prevent excessive cool down.

In a control method according to an embodiment, the temperature sensors50 include one or more thermocouples embedded on the surface of thecatalyst substrate at some point along its length such as at theconverter mid-point. The thermocouple(s) provide direct feedback to thecontroller 52 with no calculation or inference being required.Calibration is first performed to compensate for offset between theoutside and inside of the catalyst substrate. At steady state, thegreatest heat losses from the catalytic converter 60 are at itsperiphery with convection from driving, with rainwater, snow and icecontributing to the losses. During preheating, the perimeter, core, orentire substrate is heated to light-off temperature with compensationbeing made for the calculated offset in temperature between thelight-off temperature of the desired region relative to the temperaturesensor(s) 50.

While described above in conjunction with the use of separatetemperature sensors 50, in addition or in the alternative, thecontroller 52 can use the coil 20 itself for temperature tracking. Inparticular, inductance of the coil 20 falls off with increasingtemperature as molecular vibration from heat interfere with the magneticfield. Colder temperatures produce less interference than hottertemperatures. This interference can be characterized and, from it, abulk temperature can be determined by the controller 52. The substrateis the most massive component of the induction system and heat containedwithin the substrate has the greatest influence on inductance. Themonitored temperature in this method is an average temperature as thepresence of hot and cold spots is not detected. Use of the inductioncoil method obviates the need for an extra wire to the catalyticconverter.

Although control methods and apparatus have been described in thecontext of induction heating, similar control methods and apparatus arealso applied to control electrohydrodynamic (EHD) heat and masstransfer. It should be noted that controller 52 can be configured togenerate the control signals 58 and 66 to operate the induction heatingand EHD processes independently—together or at separate times.

In one example, the induction heating process is implemented beforeengine start-up, for a short time after start up, during idling andduring deceleration. The controller 52 is configured to generate controlsignal 66 to switch on the EHD process only when the engine is runningbecause the process depends on the flow of exhaust gas through theconverter. In this example, the EHD process is run at any time thatthere is flow of exhaust gas through the converter. In another example,the same or similar induction heating program is adopted but EHD processis switched off at a temperature above light-off.

While the battery 62 is shown as providing power to the EHD process, itshould be noted that a battery such as a vehicle battery can be used toselectively power the other components of the catalytic converter system75. In other examples, an alternative power source such as a solar cell,external plug in vehicle power such as provided in conjunction with ablock heater or hybrid vehicle plug in system can also be used to powerthe components of the catalytic converter system 75 in circumstanceswhere alternative power is available. In operation, the inductionheating and EHD processes can be selectively enabled or disabled undercontrol of the controller 52. In various embodiments, inductive heatingcan be initiated by the controller 52 in response to conditions such as:key in the ignition, key strike to run position; key strike to startposition, proximity of the key within X feet of vehicle, initiation of aremote start function, plug-in vehicle to grid, block heater plug-in,etc. The operations of controller 52 can be disabled in response tolight-off temperature achieved, battery state of charge too low, batteryreserve required for starter reached, manual shut-off of the system,shut-off of the engine, etc.

In should be noted that the vehicle engine can operate via one or moreof the following fuel types including gasoline, diesel, propane,ethanol, natural gas, etc. The control methodologies can be applied tovehicle operating configurations including fulltime conventionalinternal combustion, hybrid-series, parallel, mild parallel,series-parallel or power-split, plug-in hybrid electric, mild hybridauto start-stop, range extended, constant RPM engines, variable RPMengines, or other configurations. The vehicle engine can be normallyaspirated, turbo-charged, super-charged, gas-direct-injected,electronic-fuel-injected, operate via a distributor or othertechnologies.

The catalytic converter 60 can operate via platinum, palladium, rhodiumor other catalyst and can include a diesel oxidation catalyst,particulate filter and/or urea injection system. The substrate caninclude ceramic honeycomb, woven metal, a porous membrane or othersubstrate. The catalytic converter system can be directed to reducingexhaust emissions such as hydrocarbons, carbon monoxide, carbon dioxide,oxides of nitrogen, sulphur dioxide, particulate matter and/or otheremissions to a full range of air-fuel ratios (lambda) such asstoichiometric, rich-burn, lean-burn and/or other ratios.

Further examples regarding the catalytic converter system 75, includingseveral optional functions and features, are presented in conjunctionwith FIGS. 19-22 that follow.

FIG. 19 is a block diagram representation of a feedback control loopaccording to an embodiment of the disclosure. In particular a feedbackcontrol loop 100 is presented where heating of a catalytic converter,such as induction heating of the catalytic converter 60 presented inconjunction with FIG. 18, is represented by a transfer function G(s),the control signal 58 is represented by the signal E(s), a control inputis represented by the signal X(s), and the temperature of the catalyticconverter is represented by signal Y(s), The operation of the controllerand temperature sensor, such as controller 52 and temperature sensor 50,are represented by the feedback function H(s), the generation of controlinput X(s) and summing junction 102. Because the heating and convectivecooling of the of the catalytic converter can also impacted by thetemperature and volume of exhaust gases and the speed of the vehicle,these additional factors are represented by the disturbance input D(s)at summing junction 104. Each of these signals quantities arerepresented in the Laplace transform domain via the Laplace transformvariable, s.

The output temperature Y(s) can be calculated as follows:

Y(s)=G(s)[X(s)−Y(s)H(s)]+D(s)

Or,

Y(s)=D(s)+X(s)[G(s)/[1+G(s)/H(s)]]

Consider an example where the transfer function G(s) is modelled as afirst-order system as follows:

G(s)=a/(s+ω)

And further, a cold start condition where D(s)=T_(am), the feedbackfunction H(s)=k, corresponding to simple proportional control. In thiscase,

Y(s)=T _(am) +X(s)[a/(s+ω+ka)]

Considering further that the ambient temperature is T_(am), thecontroller seeks to use induction heating to maintain a referencetemperature T_(ref), and the control input is initiated via a stepfunction at a time t₀=0 with a magnitude kT_(ref). Then the temperatureof the catalytic converter in the time domain y(t) can be found from theinverse Laplace transform as:

X(s)=kT _(ref) /s

Y(s)=T _(am) +kT _(ref) a/[s(s+ω+ka)]

y(t)=L ⁻¹ [Y(s)]=T _(am)+(T _(ref) −T _(am))(1−e ^(−t/τ))

where τ=1/(ω+ka). In this case, the value of the control signal in thetime domain e(t) for times t>0 is simply:

e(t)=k[T _(ref) −y(t)]

It should be noted that the value of e(t) may be limited by thefollowing inequality:

0≦e(t)≦e _(max)

Where e_(max) represents the maximum output of the AC source 64. Notethat, in most implementations, the induction heating capability does notextend to active cooling—with cooling of the catalytic converterhappening normally via thermal radiation and convection. Thereforenegative values of the e(t) may not be permitted.

An example of operation of such a feedback control loop is presented inconjunction with FIG. 20. While the foregoing has assumed a first-ordermodel for the transfer function G(s), other higher order models withmultiple poles and zeros can likewise be employed, based on the actualtransfer function of the induction heating system and catalyticconverter that are implemented. In addition, while a feedback functioncorresponding to proportional control has been described above, othermore advanced feedback functions implementing proportional, integral,derivative control, and/or more other feedback functions with multiplepoles and zeros can likewise be employed. In addition, while aparticular feedback control loop is implemented, other controltechniques such as feed-forward control; state-space control includingoptimal control, model predictive control, linear-quadratic-Gaussiancontrol; adaptive control; hierarchical control; intelligent controltechniques using various AI computing approaches like neural networks,Bayesian probability, fuzzy logic, machine learning, evolutionarycomputation and genetic algorithms; robust control; stochastic control;non-linear control and/or other control algorithms.

FIG. 20 presents graphical representations of a control signal andcatalytic converter temperature according to an embodiment of thedisclosure. In particular a graph 110 of the control signal e(t) and agraph 110′ of the temperature of the catalytic converter are plotted inthe time domain in accordance with the example presented in conjunctionwith FIG. 19 in a cold start beginning at time t₀=0. As discussed,

y(t)=T _(am)+(T _(ref) −T _(am))(1−e ^(−t/τ))

and

e(t)=k[T _(ref) −y(t)]

As shown, the temperature y(t) begins at the ambient temperature T_(am).When the control e(t) is applied at t₀=0, the induction heating causesthe catalytic converter temperature to rise and asymptotically approachand hold a reference temperature T_(ref), such as the minimum light-offtemperature required for efficient catalytic conversion. At a time t₁,the temperature of the catalytic converter has reached the T_(ref)within an acceptable tolerance and the vehicle engine can be startedwith emission controls being fully functional. Also, at a time t₁, thecontrol signal e(t) has approached zero because the catalytic convertertemperature has approached its reference temperature and heating is nolonger required.

It should be noted that the graphs 110 and 110′ only reflect theoperation of an example catalytic converter system to a cold startcondition. Once the vehicle engine starts and the vehicle begins tomove, D(s) is no longer simply T_(am). Exhaust gases from the vehicleengine contribute heat and motion of the vehicle increases convectionand heat loss. The controller 52 responds to these changes in conditionsto maintain the temperature of the catalytic converter to a value thatis at or above the reference temperature.

FIG. 21 is a block diagram representation of a controller according toan embodiment of the disclosure. In particular, a controller 120 ispresented that can operate in a catalytic converter system and operateas a substitute for controller 52 presented in conjunction with FIG. 19.Like the controller 52, controller 120 operates to generate the controlsignal 58 for controlling the induction heating of the catalytic andcontrol signal 66 for controlling the EHD process of the catalyticconverter. Instead of operating only based on temperature data 130 fromone or more temperature sensors 50 associated with the catalyticconverter, the controller 120 operates based on a wider range of vehiclecontrol data 125 such as ambient temperature data 132, engine RPM data134 that indicates the rotational velocity of the vehicle engine, brakeactivation data 136, clutch activation data 138, remaining battery lifedata 140, stop-start mode data 142, emissions data 144, engine startdata 146, speed data 148 that indicates the speed of the vehicle,traffic data and vehicle navigation data 150 that indicates the path ofthe vehicle, speed limits, current traffic congestion, stop and goconditions, etc. and optionally other engine control data, vehiclestatus data, and vehicle data such as oxygen sensor voltage, oxygensensor temperature, exhaust gas recirculation temperature, coolanttemperature, vehicle acceleration/deceleration, air-fuel ratio (lambda),ignition position, engine timing, exhaust manifold temperature, etc.

In various embodiments, the controller 120 includes a processor and amemory that stores a look-up table (LUT) 122 that responds to the statesof the vehicle indicated by the vehicle control data 125 and generatescontrol signals 58 and 66 that corresponds to the current states. Forexample, the LUT 122 can store control data in accordance with astate-space control algorithm based on vehicle states such as catalyticconverter temperature, ambient temperature, vehicle RPM, vehicle speedindicated by temperature data 130, ambient temperature data 132, RPMdata 134, and vehicle speed data 148. In this fashion, the temperatureof the catalytic converter can be controlled based on changes in exhaustvolume caused by variations in vehicle engine RPM, changes in ambienttemperature, and heat loss due to convection at different vehiclespeeds.

In addition, the controller 120 compares the temperature data 130 withthe reference temperature, such as the light-off temperature of thecatalytic converter. The controller 120 generates an at-temperatureindication signal 152 that indicates when the temperature of thecatalytic converter has reached or is being maintained at or above thereference temperature. This at-temperature indication signal 152 can beused to trigger at-temperature indicator 160, such as a dashboard light,pop-up message on a dash board screen or other user interface thatindicates to the driver of the vehicle when the catalytic converter hasreached or is being maintained at or above the reference temperature, orthat it is ok to start the vehicle. The at-temperature indication signal152 can also be used to trigger vehicle start lock-out 170 as part ofthe vehicle ignition system that enables the vehicle engine to bestarted only when the catalytic converter has reached or is beingmaintained at or above the reference temperature.

Most vehicles now being manufactured are equipped with a wirelesscommunication device in the form of a keyless remote which typicallyincludes door lock, door unlock, trunk release, panic alarm, and,occasionally, remote start capabilities. Smartphone technology is likelyto replace the keyless remote at some point in the future and is alreadyused by some manufactures to enable remote start features via asmartphone application (“app”). In one embodiment, control of catalyticconverter preheating is incorporated into a wireless control device suchas those mentioned previously. In particular, an induction preheatingstart procedure is initiated as part of a remote start procedure, theconverter preheat procedure being initiated at a fixed or selectableperiod of time before the remote engine start is activated. In analternative, the remote wireless control device includes a dedicatedcircuit wherein converter preheating procedure is activatedindependently of any other remote control capability for the vehicle.

With the press of the preheat button or remote start, a vehiclecommunication system receives a wireless communication signal that isused to generate start data 146. In response, the controller 120generates control signal 58 to begin control of the inductively heatedcatalytic converter system. Warming the catalytic converter either tothe light-off temperature or to a temperature close to the light-offtemperature before the vehicle is started, produces less pollutants ingaseous emissions when an engine is cold started. Using a wirelessremote obviates the driver from needing to be in the vehicle in order toperform the preheating procedure because many consumers may not toleratea delay in the normal start-up procedure. In this way, the driver canget into the vehicle, switch on the ignition to start the vehicle, andthen drive away using a hot converter. As an alternative to thisprocedure, the driver enters the vehicle and turns or presses theignition key which generates the start data 146. However, in this case,a delay can be automatically instituted between the time that theignition key is pressed and the time at which the ignition circuit isenergized. During the period of this delay, the controller 120 initiatesthe converter preheating procedure. When the vehicle engine is started,the controller 120 can respond by generating control signal 66 to enablethe EHD process to achieve further efficiency.

Other vehicle control data 125 can be used by controller 120 to generatethe control signals 58 and 66 and/or to adapt the operation ofcontroller 120 to differing vehicle states and conditions. Currentconverter technology uses pre-converter and post-converter oxygensensors to calculate the effective catalytic converter temperature withthe discrepancy between the sensors providing a measure of the convertertemperature. Emissions data 144 generated by these oxygen sensors orfrom other emissions sensors of the vehicle can be used by controller120. For example, when no difference is detected in the emissions data144 between input and output oxygen sensors, the catalyst is not workingso the temperature is below light-off (300 C). Above 300 C, thedifference between the sensors grows and the calculated temperatureincreases proportionately with oxygen conversion. This emissions data144 can be used to supplement the temperature data 130, detecttemperature sensor failure etc.

As previously discussed, in mild hybrid vehicles and electric hybridvehicles, the vehicle engine can be automatically turned-off andrestarted during vehicle operation. Extended stoppage of the vehicleengine during operation can cause the catalytic converter to cool belowthe minimum light-off temperature and increase vehicle emissions. Invarious embodiments, the controller 120 can be adapted to autostart-stop operation. In particular, start-stop mode data 142 canindicate whether auto start-stop functionality is enabled or disabled onvehicles that include this functionality. When auto start-stopfunctionality is enabled, the RPM data 134 can indicate whether theengine is started or stopped. Brake data 136, clutch data 138 andvehicle speed data 148 can further indicate to controller 120 when anauto stop may be imminent. In an embodiment, the controller 120 respondsto starting and stopping of the vehicle engine by generating controldata 66 to start and stop the EHD process in a synchronous fashion. Inaddition, the controller 120 can generate control data 52 to maintainthe temperature of the catalytic converter when the engine is stopped,preventing a cold start condition when the engine is subsequentlyrestarted.

In a further embodiment, the controller 120 includes a drive modeprediction generator 124 analyzes the vehicle control data 125 in orderto predict a current driving mode from a set of possible driving modessuch as:

-   -   (a) a non-hybrid stop-and-go traffic mode characterized by        continuous vehicle engine operation, frequent an/or extended        stops accompanied by idling    -   (b) a highway mode characterized by continuous vehicle engine        operation, high vehicle speeds, limited braking and clutch        operation, moderate RPM and high rates of convection;    -   (c) an extended idle mode where the vehicle is running but        stopped for an extended length of time;    -   (d) an auto start-stop stop-and-go traffic mode characterized by        frequent an/or extended stops accompanied by auto start-stop;    -   (e) an electric-only mode of a hybrid vehicle where the vehicle        engine is stopped and is may not be started until the        electric-only mode is exited;    -   (f) hybrid electric mode where the vehicle engine may be stopped        for extended periods and restarted only when required, etc.        The controller adaptively generates the control signal 58 in        accordance with the current driving modes. In non-hybrid        stop-and-go traffic mode, extended idle mode or highway mode,        the controller 120 can generate the control signals 58 as        previously discussed to trigger inductive heating, only as        required to maintain the temperature of the catalytic converter        at or above the light-off temperature. In auto start-stop        stop-and-go traffic mode, the controller 120, for shorter stops,        can generate the control signals 58 as previously discussed to        trigger inductive heating, only as required to maintain the        temperature of the catalytic converter at or above the light-off        temperature. For longer stops that can be predicted based on a        pattern caused by stop and go commuter traffic or traffic light        stops, based on traffic data and navigation 150, or based on        other driving patterns, the controller 120 may allow the        temperature of the catalytic converter to fall below the        light-off temperature for short periods as long as the        controller predicts that reheating to light-off temperature can        be initiated and completed before the controller 120 predicts        that a restart will occur. For example, the controller 120 can        operate to control the catalytic converter temperature to a        standby temperature that is lower than the light-off        temperature. The standby temperature can be selected to save        power, but be close enough to the light-off temperature so as to        minimize the reheating time required to return the catalytic        converter temperature to light-off for vehicle engine restart.        While the foregoing has considered particular driving modes, the        controller 120 can also predict and adapt to other driving modes        such as aggressive driving, timid driving, hypermiling, etc.

Likewise, in hybrid electric mode, the controller may allow thetemperature of the catalytic converter to fall below the light-offtemperature as long as the controller predicts that reheating tolight-off temperature can be initiated and completed before thecontroller 120 predicts that a restart will occur. In an embodimentauto-start data from the engine control module may indicate based onvehicle speed, navigation route guidance, traffic conditions, that arestart of the engine is imminent and may initiate heating from thecurrent temperature or from a standby temperature to light-offtemperature, as required, for completion before the controller 120predicts that a restart will occur. Further in electric-only mode of ahybrid vehicle, the controller may pre-heat the catalytic converter onlywhen electric only mode is exited or when the controller 120 predictsthat a restart of the vehicle engine will occur.

Converter preheating power can be, as previously discussed, providedfrom an on-board battery. Car batteries can supply heating power onlyfor a short period of time depending on the power draw. Preheating withthe vehicle engine off may be more limited due to lower battery voltageswhen compared with cases where the car engine is running and aconsistent 14 VDC is available from the car battery. Diesel cars andtrucks typically have larger batteries than regular gas cars owing tothe use of glow plugs which must be preheated in order to facilitate thecombustion process. Diesel vehicles generally have more availableonboard electrical power than conventional cars. Hybrid electricvehicles have large amounts of battery capacity, however they rely onthis capacity to enhance vehicle range and lower the cost of operation.

In an embodiment, the controller 120 generates the control signals 58and 66 in accordance with a low power mode when the remaining charge inthe battery compares unfavorably with a low power threshold. Thecatalytic converter heating is initiated by controller 120 andmaintained for as long as possible commensurate with maintainingsufficient battery power to start the car. The power level of thebattery is monitored prior to and during the converter preheatingprocedure and battery life data 140 indicating the remaining batterylife is used by the controller 120 to enter a low power mode. In thislow power mode, for example, the controller can disable the inductionheating and EHD processes from the onset or stop the induction heatingand/or EHD processes when the remaining battery life is, or falls belowa minimum reliable power threshold indicating that further use couldcompromise a vehicle start or other vehicle operation.

Converter preheating power can optionally be provided from the utilitygrid. The use of grid power is current practice for range-extendedhybrid, plug-in hybrid, block-heater, and electric vehicles. The car isplugged in either at a standard receptacle or a vehicle-specificreceptacle. Block-heaters are typically used in cold climates especiallywith diesel engines. Plugging in the block-heater keeps the enginecoolant warmed to enable easier starts and to prevent coolant fromfreezing. Grid power is used both to maintain batteries in a fullycharged condition and also to prepare the battery pack for driving use.Batteries do not operate well in conditions of extreme cold or extremeheat and battery packs providing a climate control system are used tomaintain the battery temperature at a moderate temperature enablingmaximum power.

For example, grid power from a garage or public place receptacle can beused inductively to preheat the catalytic converter of internalcombustion vehicles. In this approach there is no limitation on heat-upperiod as compared to running directly off the onboard battery. Of note,grid power is one-fifth the cost of gasoline for the same energyproduced and because a vehicle will often be at its home location orwith access to a public receptacle, preheating using grid can be usedfor most cold start conditions. To activate, in one variation, thekeyless entry, smartphone or other wireless command is used to preheatthe converter for a predetermined period before the driver gets in anddrives away. In an alternative, the keyless remote feature is used topreheat the catalyst for a predetermined time before the car isautomatically started. This ensures that the emissions are as clean aspossible upon start-up and while still allowing the consumer to have theremote start feature. Inductively heating the converter is onlyperformed until the light-off temperature is achieved because there islittle to no benefit in exceeding the light-off temperature.

In various embodiments, the controller 120 is coupled to communicatewith a connected car interface 175 of the vehicle that provides featuressuch as vehicle Internet access, wireless connectivity between thevehicle and wireless user devices such as a smartphone, tablet,smartwatch, laptop computer or other computing device, as well aswireless access for use in service and vehicle diagnostics, vehicleinspections and other connectivity. Emissions data 144 received from anengine control module or from separate emission sensors can be processedand/or stored in a memory associated with the controller 120 in order toprovide a historical record of actual vehicle emissions.

This historical emissions data can be retrieved via the connected carinterface 175 and provided to a user smartphone, tablet, home computeror other user device for the purposes of maintaining a record of vehicleemissions. In addition, the historical emissions data can be provided aspart of a vehicle inspection that requires a test of not only currentemissions, but also of historical emissions data. Further, thehistorical emissions data can be provided to service personnel to use invehicle diagnostics and repair.

The data indicating actual vehicle emissions can be used for otherpurposes. For example, the connected car interface 175 can provide thisdata to an in-dash display, user smart phone or tablet or other displayscreen as part of an application or utility that presents a display ofcurrent emissions to the occupants of the vehicle during a trip. In asimilar fashion, control data 58 and 66 indicating the activation of theinduction heating and/or EHDC processes can be provided to the connectedcar interface 175 and indicated on the display, letting the occupants ofthe vehicle know that, for example, these systems are operating toreduce emissions. The application or utility can optionally provide acomparison of actual emissions to theoretical emissions had theinduction heating and/or EHDC processes not been in operation anddisplay to the vehicle occupants the benefits, in terms of reducedemissions, provided by these systems. In a further example, dataindicating the maintenance of low emissions goals by the vehicle can bereported via the connected car interface 175 and used to qualify thevehicle owner for tax credits, high occupancy vehicle status, rewards orother incentives.

FIG. 22 is a flow diagram representation of a method according to anembodiment of the disclosure. In particular, a method is presented foruse in conjunction with one or more functions and features presented inconjunction with FIGS. 1-21. Step 200 includes generating a temperaturesignal indicating a temperature of a catalytic converter. Step 202includes generating a control signal based on the temperature signal.Step 204 includes generating an electromagnetic field to inductively toheat the catalytic converter in response to the control signal.

In various embodiments, the control signal is generated further based ona reference temperature, to control the temperature of the catalyticconverter in accordance with the reference temperature. The method canfurther include generating an at temperature signal indication signalwhen the at least one temperature of the catalytic converter comparesfavorably to the reference temperature. Start-up of a vehicle engine canbe enabled in response the at temperature signal indication signal.

In various embodiments, the controller generates the control signalfurther based on at least one of: a signal indicating a rotationalvelocity of the vehicle engine; a signal indicating an ambienttemperature of the vehicle containing the catalytic converter system; asignal indicating an auto start-stop mode of the vehicle engine; asignal indicating a remaining charge in a vehicle battery. The methodcan further include predicting a current one of a plurality of drivingmodes based on vehicle control data and the control signal can begenerated in accordance with the current one of the plurality of drivingmodes. The method can further include controlling an electrohydrodynamicheat/mass transfer process of the catalytic converter system.

It is noted that terminologies as may be used herein such as bit stream,stream, signal sequence, etc. (or their equivalents) have been usedinterchangeably to describe digital information whose contentcorresponds to any of a number of desired types (e.g., data, video,speech, audio, etc. any of which may generally be referred to as‘data’).

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “configured to”, “operably coupled to”, “coupled to”, and/or“coupling” includes direct coupling between items and/or indirectcoupling between items via an intervening item (e.g., an item includes,but is not limited to, a component, an element, a circuit, and/or amodule) where, for an example of indirect coupling, the intervening itemdoes not modify the information of a signal but may adjust its currentlevel, voltage level, and/or power level. As may further be used herein,inferred coupling (i.e., where one element is coupled to another elementby inference) includes direct and indirect coupling between two items inthe same manner as “coupled to”. As may even further be used herein, theterm “configured to”, “operable to”, “coupled to”, or “operably coupledto” indicates that an item includes one or more of power connections,input(s), output(s), etc., to perform, when activated, one or more itscorresponding functions and may further include inferred coupling to oneor more other items. As may still further be used herein, the term“associated with”, includes direct and/or indirect coupling of separateitems and/or one item being embedded within another item.

As may be used herein, the term “compares favorably”, indicates that acomparison between two or more items, signals, etc., provides a desiredrelationship. For example, when the desired relationship is that signal1 has a greater magnitude than signal 2, a favorable comparison may beachieved when the magnitude of signal 1 is greater than that of signal 2or when the magnitude of signal 2 is less than that of signal 1. As maybe used herein, the term “compares unfavorably”, indicates that acomparison between two or more items, signals, etc., fails to providethe desired relationship.

As may also be used herein, the terms “processing module”, “processingcircuit”, “processor”, and/or “processing unit” may be a singleprocessing device or a plurality of processing devices. Such aprocessing device may be a microprocessor, micro-controller, digitalsignal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on hard coding of thecircuitry and/or operational instructions. The processing module,module, processing circuit, and/or processing unit may be, or furtherinclude, memory and/or an integrated memory element, which may be asingle memory device, a plurality of memory devices, and/or embeddedcircuitry of another processing module, module, processing circuit,and/or processing unit. Such a memory device may be a read-only memory,random access memory, volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, cache memory, and/or any devicethat stores digital information. Note that if the processing module,module, processing circuit, and/or processing unit includes more thanone processing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

One or more embodiments have been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claims. Further, the boundariesof these functional building blocks have been arbitrarily defined forconvenience of description. Alternate boundaries could be defined aslong as the certain significant functions are appropriately performed.Similarly, flow diagram blocks may also have been arbitrarily definedherein to illustrate certain significant functionality.

To the extent used, the flow diagram block boundaries and sequence couldhave been defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claims. One of average skill in the art will alsorecognize that the functional building blocks, and other illustrativeblocks, modules and components herein, can be implemented as illustratedor by discrete components, application specific integrated circuits,processors executing appropriate software and the like or anycombination thereof.

In addition, a flow diagram may include a “start” and/or “continue”indication. The “start” and “continue” indications reflect that thesteps presented can optionally be incorporated in or otherwise used inconjunction with other routines. In this context, “start” indicates thebeginning of the first step presented and may be preceded by otheractivities not specifically shown. Further, the “continue” indicationreflects that the steps presented may be performed multiple times and/ormay be succeeded by other activities not specifically shown. Further,while a flow diagram indicates a particular ordering of steps, otherorderings are likewise possible provided that the principles ofcausality are maintained.

The one or more embodiments are used herein to illustrate one or moreaspects, one or more features, one or more concepts, and/or one or moreexamples. A physical embodiment of an apparatus, an article ofmanufacture, a machine, and/or of a process may include one or more ofthe aspects, features, concepts, examples, etc. described with referenceto one or more of the embodiments discussed herein. Further, from figureto figure, the embodiments may incorporate the same or similarly namedfunctions, steps, modules, etc. that may use the same or differentreference numbers and, as such, the functions, steps, modules, etc. maybe the same or similar functions, steps, modules, etc. or differentones.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of one or more of theembodiments. A module implements one or more functions via a device suchas a processor or other processing device or other hardware that mayinclude or operate in association with a memory that stores operationalinstructions. A module may operate independently and/or in conjunctionwith software and/or firmware. As also used herein, a module may containone or more sub-modules, each of which may be one or more modules.

While particular combinations of various functions and features of theone or more embodiments have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent disclosure is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

What is claimed is:
 1. A catalytic converter system comprising: a catalytic converter having a plurality of passages to facilitate at least one catalytic reaction in an exhaust gas from a vehicle engine; a temperature sensor, coupled to the catalytic converter, that generates a temperature signal indicating at least one temperature of the catalytic converter; an electromagnetic field generator that responds to a control signal by generating an electromagnetic field to inductively to heat the catalytic converter; and a controller, coupled to the temperature sensor and the electromagnetic field generator, that generates the control signal based on temperature signal.
 2. The catalytic converter system of claim 1 wherein the controller generates the control signal further based on a reference temperature.
 3. The catalytic converter system of claim 2 wherein the controller generates the control signal further to control the at least one temperature of the catalytic converter in accordance with the reference temperature.
 4. The catalytic converter system of claim 3 wherein the controller generates an at temperature signal indication signal when the at least one temperature of the catalytic converter compares favorably to the reference temperature.
 5. The catalytic converter system of claim 4 further comprising: an at temperature indicator, coupled to the controller, that generates an at temperature indication to a driver of a vehicle containing the catalytic converter system in response to the at temperature signal indication signal.
 6. The catalytic converter system of claim 4 wherein start-up of the vehicle engine is enabled in response the at temperature signal indication signal.
 7. The catalytic converter system of claim 1 wherein the controller generates the control signal further based on a signal indicating a rotational velocity of the vehicle engine.
 8. The catalytic converter system of claim 1 wherein the controller generates the control signal further based on a signal indicating an ambient temperature of the vehicle containing the catalytic converter system.
 9. The catalytic converter system of claim 1 wherein the controller generates the control signal further based on a signal indicating an auto start-stop mode of the vehicle engine.
 10. The catalytic converter system of claim 1 wherein the electromagnetic field generator operates based on power from a battery and the controller generates the control signal further based on a signal indicating remaining charge in the battery.
 11. The catalytic converter system of claim 10 wherein the controller generates the control signal in accordance with a low power mode when the remaining charge in the battery compares unfavorably with a low power threshold.
 12. The catalytic converter system of claim 1 wherein the controller includes a driving mode prediction generator that predicts a current one of a plurality of driving modes based on vehicle control data and wherein the controller adaptively generates the control signal in accordance with the current one of the plurality of driving modes.
 13. The catalytic converter system of claim 1 wherein the controller further controls an electrohydrodynamic heat/mass transfer process of the catalytic converter system.
 14. A method comprising: generating a temperature signal indicating a temperature of a catalytic converter; generating a control signal based on the temperature signal; and generating an electromagnetic field to inductively to heat the catalytic converter in response to the control signal.
 15. The method of claim 14 the control signal is generated further based on a reference temperature, to control the temperature of the catalytic converter in accordance with the reference temperature.
 16. The method of claim 15 further comprising: generating an at temperature signal indication signal when the temperature of the catalytic converter compares favorably to the reference temperature.
 17. The method of claim 16 wherein start-up of a vehicle engine is enabled in response the at temperature signal indication signal.
 18. The method of claim 14 wherein the controller generates the control signal further based on at least one of: a signal indicating a rotational velocity of a vehicle engine; a signal indicating an ambient temperature of a vehicle; a signal indicating an auto start-stop mode of the vehicle engine; a signal indicating a remaining charge in a vehicle battery.
 19. The method of claim 14 further comprising: predicting a current one of a plurality of driving modes based on vehicle control data; the control signal is generated in accordance with the current one of the plurality of driving modes.
 20. The method of claim 14 further comprising: controlling an electrohydrodynamic heat/mass transfer process of the catalytic converter. 